多通道柱状施源器端到端测试  

End-To-End Test of Multi-channel Cylinder Applicator

作　　者：于浪[1] 杨波[1] 刘峡[1] 庞廷田[1] 刘楠[1] 李文博[1] 董婷婷[1] 王贝 汪之群 张杰[1] 梁永广 邱杰[1] YU Lang;YANG Bo;LIU Xia;PANG Tingtian;LIU Nan;LI Wenbo;DONG Tingting;WANG Bei;WANG Zhiqun;ZHANG Jie;LIANG Yongguang;QIU Jie(Department of Radiotherapy,Peking Union Medical College Hospital,Beijing 100730,China)

机构地区：[1]北京协和医院放疗科,北京100730

出　　处：《中国医疗设备》2021年第4期104-107,126,共5页China Medical Devices

基　　金：“十三五”国家重点研发计划项目(2016YFC0105206,2016YFC0105207)。

摘　　要：目的确认多通道柱状施源器采用模板重建的参数设置,并完成投入临床使用前的端到端测试。方法利用自制3D打印模体,多通道柱状施源器、CC13电离室和EBT3免洗胶片构建ETE模体。分别在施源器头尾两端设置靶区1和靶区2,完成处方剂量分别为5~7 Gy模拟计划设计并进行照射,获得实测点剂量及面剂量,与TPS剂量进行比较。以2 mm/2%、10%的剂量阈值作为评价标准,面剂量分布差异采用γ分析方法进行分析。结果多通道柱状施源器各重建参数符合标称范围,采用施源器模板进行重建后参数需做部分更改,中央管道的顶端tip length更改为5.8 mm,周围管道顶端tip length更改为4 mm并将其出源长度更正为1493 mm。电离室测量偏差为0.97±0.32%,其中高剂量区的偏差值小于低剂量区;胶片面测量结果与计划系统面剂量分布符合良好,矢状面γ通过率分别为97.4%、98.2%和98.8%,水平面通过率分别为99.3%、98.4%和98.7%,平均γ通过率为98.5±0.63%。结论新型柱状多通道施源器投入临床使用前须对参数进行测量用于重建施源器时的参数设置,经过ETE测试确认该施源器点剂量及面剂量测量结果良好,为该施源器正确用于临床提供依据。Objective To verify the reconstruction parameters of the multi-channel cylinder applicator from template,and to complete the end-to-end test before clinical use.Methods The 3D printed self-made phantom,multi-channel applicator,CC13 ionization chamber and EBT3 film was used to complete the ETE test.Target area 1 and target area 2 were set at both ends of the applicator,respectively,to complete the simulation plan design of the prescribed dose of 5~7 Gy and conduct irradiation,to obtain the measured point dose and surface dose,and compare with the TPS dose.The dose thresholds of 2 mm/2% and 10% were used as evaluation criteria,and the difference of plane dose distribution was analyzed by γ method.Results The reconstruction parameters of the multi-channel cylinder meet the nominal range.After the reconstruction using the TPS template,the parameters need to be partially changed.The tip length at the top of the central catheter is changed to 5.8 mm,and the surrounding catheters are changed to 4 mm,of which the source length is corrected to 1493 mm.The measurement deviation of ionization chamber was 0.97±0.32%,and the deviation of high dose area was smaller than that of low dose area.The results of the film dose analysis were in good agreement with the dose distribution of the TPS.The passing rate ofγin the sagittal plane was 97.4%,98.2% and 98.8%,in the horizontal plane was 99.3%,98.4% and 98.7%,respectively.The average passing rate ofγwas 98.5±0.63%.Conclusion Parameters of the new type of multi-channel cylinder applicator should be measured before clinical use and to adjust the parameters of the template accordingly.Through the ETE test,it is confirmed that the point dose and plane dose measurement results are satisfactory,which support the applicator for clinical use.

关 键 词：后装放射治疗 多通道施源器 端到端测试 残端照射 

分 类 号：R734.4[医药卫生—肿瘤]